So far, my experience since the updates hasn't been terribly positive. I was not able to get my SP4 to consistently sleep this morning--I'd close the Type Cover and come back after a time, the back would be warm to the touch and battery life was burning at a 6-7% clip. Also, if the fan is running and I try to put it to sleep, the fan never stops--presumably, this means it isn't sleeping.
So, I thought I'd perform a factory reset following just to ensure there were no conflicting drivers or such. After the Settings reset failed and the SP4 went into an endless loop, I create a USB restore disk and used that to perform the reset. Now, I'm not finding the SP4 to sleep at all as far as I can tell, and when the screen goes off and I try to recover it, the SP4 won't wake up. I need to perform a 2-button shutdown to restart. This has happened twice.
So, either the update is flawed, or my SP4 is. Not terribly happy as one can imagine.